A reduced train timetable is set to be imposed on the Thameslink line due to staff self-isolating because of Covid.

Thameslink and Southern will be introducing the revised timetable on Monday, with passengers strongly advised to check services before they travel.

The Thameslink routes affected are between Sutton and St Albans City via Wimbledon and via Hackbridge, and between Gatwick Airport and Bedford.

The train companies have seen a significant rise in staff needing to isolate in recent weeks, which when combined with the knock-on impact and disruption of COVID-19 over the past 17 months, means that there are fewer staff available to operate services at present.

The idea is that by bringing in a reduced weekday timetable now, passengers will have more certainty about services and experience fewer short notice cancellations, but it is still possible additional changes will need to be made on the day including at weekends.

Where possible, the weekday changes are focused on lines where there is overlap at stations with other train services or there are alternative transport choices. They have also been chosen in places where new services can be created by adding station stops on alternative trains to help passengers complete their journeys.

Steve White, chief operating officer for Govia Thameslink Railway said: “Regrettably, we have had to make the difficult decision to reduce some weekday services.

“Unfortunately, like other industries across the country, coronavirus continues to affect our operations. We have fewer colleagues available at the moment due to a significant increase recently in the number of our people affected by COVID-19.

“Our colleagues have continued to work tirelessly throughout the pandemic and we’re really sorry for any inconvenience caused by the latest changes.

“We strongly advise passengers to check before they travel, including at weekends.”

The reductions will be:

Between Sutton and St Albans City via Wimbledon and via Hackbridge

One train per hour will travel via Wimbledon and one train per hour will travel via Hackbridge to create a two trains per hour service in the Streatham to St Albans City section.

Between Gatwick Airport and Bedford

The service group between Bedford and Gatwick Airport via Horley, Salfords, Earlswood and Redhill will not run. Alternative trains will call at Earlswood and Salfords hourly throughout the day.

This will mean a reduced service from Bedford to London with two services between Bedford, London and Brighton running per hour. During the peak hours there are extra trains that will still run during this amended timetable.